254 PINE. 



It is also desirable, before shaking, to put a band of some 

 nature that the caterpillars will not cross on the ground at the 

 foot of the tree, to keep all that may have escaped from 

 making good their return up the trunk. 



Quick-lime would answer this purpose, or gas-lime ; or a 

 hay-band (or pieces of any old rags twisted together into a 

 rope) well tarred or soaked in a mixture of tar and oil that 

 would keep wet and sticky for some time, would be a sure 

 preventive of traffic of the caterpillars across it. 



When the caterpillars have consumed the leafage on one 

 tree, they migrate to another ; and where tracts of forest are 

 affected it has been advised to dig ditches not less than two 

 feet deep and two feet broad, with the sides as perpendicular 

 as possible. Looking at the clinging poAvers of the caterpillars, 

 it does not seem likely that this plan would do more than delay 

 progress, and also afford a clear space where the caterpillars, 

 when they occur in the myriads described by Hartig and 

 Kollar in the German Pine forests, might be duly dealt with by 

 regular watchers ; but, generally speaking, a broad band of 

 something which they would not cross, laid on the ground, 

 appears a more practicable remedy. 



Sand or ashes, or dry earth, well sprinkled with paraffin 

 and water, would probably check the onward progress more 

 effectually at less cost ; or a band of fresh gas-lime would be 

 effective. Quick-lime would be of little use in this case, 

 as something is needed of which the effects would last for at 

 least a few days. 



When infested and uninfested trees are mixed together, it 

 maybe worth while to isolate such as have not been attacked. 

 Save where the boughs touch, the caterpillars can only reach 

 them by crawling up the trunk, and a large number might be 

 protected at a small expense by placing rings of any deterrent 

 the forester might choose at the lowest part of the trunk, or 

 on the ground round it. A band about a foot wide of fish-oil 

 soft-soap, mixed to a thick consistency and laid on with a 

 large brush, would cost little beyond the wages of the operator, 

 and probably be a preventive. 



Something may be done just for a few small trees by 

 picking cocoons off' the leaves, or clearing them from crevices 

 on the bark, or by removing the leaves that have eggs 

 laid in them ; but these operations are not practicable on a 

 large scale. 



Unge?iial iveather acts 'poiverfidhj on this insect. — In the 

 autumn of 1880 it was noted that the first frosts, coming 

 suddenly, destroyed many of the caterpillars that still re- 

 mained on the trees at Earlston, in the south of Scotland, and 

 the absence of the Sawflies from the Athol forests, and also 



